Modulating Cell-fate to Promote Regenerative Tendon Healing

调节细胞命运促进肌腱再生愈合

• 批准号: 10208209
• 负责人: Alayna Loiselle
• 金额: $ 44.77万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-08 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10208209
• 关键词: Acute; Affect; Apoptosis; Articular Range of Motion; Biomechanics; Cell Lineage; Cells; Chronic; Cicatrix; Clinical; Coculture Techniques; Collagen Type I; Communication; Data; Deposition; Environment; Exhibits; Extracellular Matrix; Feedback; Fibroblasts; Fibrosis; Flexor; Gene Expression Profile; Heterogeneity; Immunophenotyping; Impaired healing; Impairment; Inflammation; Injury; Mediating; Molecular Profiling; Mus; Myofibroblast; NF-kappa B; Pharmacology; Phase; Phenotype; Play; Population; Production; Property; Reporter; Role; S100A4 gene; Signal Transduction; Site; System; Tendon Injuries; Tendon structure; Testing; Time; Tissue Sample; Tissues; Work; healing; improved; injury and repair; macrophage; migration; mouse model; novel; p65; paracrine; periostin; recruit; regenerative; repaired; restoration; scleraxis; single-cell RNA sequencing; therapeutic target; time use; tissue repair

Tendon injuries heal in a fibrotic manner via chronic deposition of excessive, disorganized extracellular matrix. Myofibroblasts are a critical driver of fibrosis in many tissues, and emerging evidence demonstrates myofibroblast heterogeneity. That is, myofibroblasts with unique molecular profiles that correspond to changes in myofibroblast function. Importantly, the fibroblast lineage from which myofibroblasts are derived also plays a major role in dictating myofibroblast function. However, very little is known about myofibroblast dynamics during fibrotic tendon healing, including their fibroblast/tenocyte-lineage, how their functions change over time, what the molecular profiles of these different myofibroblast subtypes are, and how myofibroblasts interact with other cells, such as macrophages, to mediate healing and fibrosis. We have identified Scleraxis-lineage and S100a4-lineage cells as the predominant myofibroblast precursor populations during tendon healing. Interestingly, depletion of S100a4-cells impairs early tendon healing, while Scx-cell depletion improves late tendon healing suggesting these cells may give rise to functionally distinct myofibroblast populations. In addition, our preliminary data identifies macrophages as a critical driver of the tenocyte-myofibroblast transition, and we observed prolonged macrophage presence during late healing, concomitant with NFB- mediated pro-survival signaling in myofibroblasts. These data are consistent with a pro-fibrotic feedback loop between macrophages and myofibroblasts to sustain fibrosis in many tissues. Thus, in the present study we will use a murine model of acute tendon injury and repair to rigorously define tenocyte lineage-specific contributions to myofibroblast fate and define myofibroblast heterogeneity during healing. We will test the central hypothesis that inhibiting macrophage-mediated myofibroblast differentiation and NF-B-mediated survival of lineage-specific myofibroblasts promotes regenerative tendon healing. We will test this hypothesis through the following specific aims: Aim 1: Define the temporal and tenocyte lineage-dependent immunophenotype of myofibroblasts during fibrotic tendon healing. Aim 2: Establish the requirement for extrinsic macrophages in fibrotic healing via modulation of the tenocyte-myofibroblast transition and test the translational potential of inhibiting macrophage recruitment. Aim 3: Demonstrate that disrupting myofibroblast survival or macrophage persistence inhibits sustained fibrosis and promotes regenerative tendon healing. Successful completion of these studies will establish myofibroblast lineage, molecular profile and activation mechanisms over time during fibrotic healing and define disruption of persistent myofibroblasts and macrophages as a novel means to improve tendon healing.

肌腱损伤以纤维化方式通过长期沉积过量的，混乱的细胞外基质。 肌纤维细胞是许多组织纤维化的关键驱动力，新兴的证据表明 肌纤维细胞异质性。也就是说，具有独特分子曲线的肌纤维细胞对应于变化 在肌纤维细胞功能中。重要的是，从中得出肌纤维细胞的成纤维细胞谱系也播放 在决定肌纤维细胞功能方面的主要作用。但是，关于肌纤维细胞动力学知之甚少 在纤维化肌腱愈合期间，包括其成纤维细胞/Tenocyte-Linege，其功能如何随着时间而变化， 这些不同的肌纤维细胞亚型的分子曲线是什么，以及肌纤维细胞如何与 其他细胞，例如巨噬细胞，用于中位愈合和纤维化。我们已经确定了巩膜和 S100A4-LINEGE细胞是肌腱愈合过程中主要的成肌纤维细胞前体群体。 有趣的是，S100A4细胞的耗竭会损害早期肌腱愈合，而SCX细胞耗竭迟到 肌腱愈合表明这些细胞可能会导致功能上不同的肌纤维细胞群体。在 此外，我们的初步数据将巨噬细胞确定为tenocte-Myofibrobrosbros的关键驱动力 过渡，我们观察到晚期愈合期间长时间的巨噬细胞存在，与NFB-伴随 肌纤维细胞中介导的促生存信号传导。这些数据与促纤维反馈循环一致 巨噬细胞和肌纤维细胞之间以维持许多组织的纤维化。在本研究中，我们 将使用急性肌腱损伤和修复的鼠模型，以严格定义tenocyte谱系特异性 对肌纤维细胞命运的贡献并定义愈合过程中肌纤维细胞异质性。我们将测试 中央假设抑制巨噬细胞介导的肌纤维细胞分化和NF-B介导的 谱系特异性肌纤维细胞的存活可促进再生肌腱愈合。我们将检验这个假设 通过以下特定目的：目标1：定义临时和替代谱系的依赖性 纤维化肌腱愈合过程中肌纤维细胞的免疫表型。目标2：确定要求 纤维化愈合中的外部巨噬细胞通过替恩氏肌纤维细胞过渡的调节并测试 抑制巨噬细胞募集的翻译潜力。目标3：证明破坏肌纤维细胞 生存或巨噬细胞持久性抑制持续的纤维化并促进再生肌腱愈合。 这些研究的成功完成将建立肌纤维细胞谱系，分子谱和激活 纤维化愈合过程中随着时间的推移机制，并定义了持续的肌纤维细胞的破坏和 巨噬细胞作为一种新颖的意思是改善肌腱愈合。